There is currently no established objective laboratory test for Long COVID. The «COVID Dogolomics» research project is therefore investigating whether the condition is associated with a characteristic scent signature. Researchers from the University of Veterinary Medicine Hannover, Hannover Medical School and Technische Universität Braunschweig are involved in the project.
Specially trained dogs examined urine samples from people with Long COVID, healthy controls and people with similar conditions. According to the research team, the dogs were able to reliably distinguish the Long COVID samples.
The same samples were subsequently analysed using mass spectrometry. This method can detect volatile organic compounds (VOCs)—metabolic products that may provide information about biological processes. Using machine learning, the research team identified characteristic patterns. The results matched the dogs’ findings remarkably well.
The fact that two fundamentally different methods detect comparable signals points to measurable metabolic changes associated with Long COVID. However, questions remain: several potentially important compounds have been identified, but their chemical structures have not yet been fully determined.
For research, this represents an interesting step towards reliable Long COVID diagnostics.
Source: Stiftung Tierärztliche Hochschule Hannover, 8 July 2026
